132 



have to await the development of a simpler test, or the setting up 

 of the organization needed for a more extensive testing on goats. 



The isolation of the active principle of the thymus is the more 

 urgent because it is not impossible that myotonia and muscular 

 dystrophy are related diseases and involve the hormonal activity of 

 the thymo-lymphatic system. 



There are also a few observations to suggest that the thymus 

 may be, in some way, involved in the production of nucleotides, 

 and thus also in the production of nucleic acids (which, in their 

 turn, are involved in protein synthesis). The extraordinar)' wealth 

 of the thymus in DNA may be taken as an indication of this. My 

 thymus extracts gave only one reaction not given by analogous 

 extracts of other organs: they altered the light emission of acridine 

 orange and acridine yellow if these dyes were added in a low 

 concentration (10"* Ai), and gave a precipitate if these dyes were 

 added in a higher concentration. The light emission (as observed 

 under the UV lamp) shifted towards the red in the case of 

 acridine orange and was quenched in the case of acridine yellow. 

 Nucleic acids and adenine nucleotides show analogous reactions 

 and the behavior of my thymus extracts could be explained by 

 their extraordinary wealth in nucleotides. The acridine-dye com- 

 plexes of nucleic substances are very stable and so it was not sur- 

 prising to learn that Lewis and Goland found that acridine dyes, 

 like trypaflavine caused an atrophy of the thymus. An attempt 

 seems to be indicated to try acridine derivatives as therapeutic 

 agents in cases of myasthenia in which the thymus is suspected to 

 be the culprit. 



The promising yellow dye which I isolated earlier from thymus 

 extracts (1955) turned out to be an oxide of ascorbic acid which 

 is especially abundant in this gland. 



